Enhanced CO₂ Detection Using Potentiometric Sensors Based on PIM‐1/DBU Imidazolate Membranes

A novel potentiometric sensor for carbon dioxide (CO 2 ) detection utilizing a composite membrane of Polymer of Intrinsic Microporosity (PIM‐1) and 18‐diazabicyclo[5.4.0]undec‐7‐ene imidazolate (DBU‐imidazolate) is presented. The high surface area and gas permeability of PIM‐1, combined with the chemical affinity and ion‐exchange properties of DBU‐imidazolate, contribute to enhanced CO 2 sensitivity and selectivity. The research objectives included the synthesis of PIM‐1 and DBU‐imidazolate, the preparation of composite membranes, and the evaluation of their performance as CO 2 sensors. Solvent casting and impregnation methods are employed to prepare the membranes, which are characterized using Thermal Gravimetric Analysis (TGA), and Field Emission Scanning Electron Microscopy (FESEM). CO₂ absorption tests and Electrochemical Impedance Spectroscopy (EIS) are conducted to assess the sensors' performance. The PIM‐1/DBU‐imidazolate membrane exhibited high efficiency in CO₂ capture and release. Open circuit voltage (OCV) measurements are performed under varying concentrations of CO 2 exposure and cycles of adsorption/desorption. Results show that the membrane achieves steady state faster at higher CO 2 concentrations, with a logarithmic relationship between CO 2 concentration and voltage variation, indicating potential for CO 2 detection in human environments. These results confirm the sensor's ability to detect varying CO 2 concentrations, highlighting its potential for reliable and efficient CO 2 monitoring in environmental and industrial applications.